function clone(data) {
    let result = {}
    const keys = [...Object.getOwnPropertyNames(data), ...Object.getOwnPropertySymbols(data)]
    if(!keys.length) return data
    keys.forEach(key => {
      let item = data[key]
      if (typeof item === 'object' && item) {
        result[key] = clone(item)
      } else {
        result[key] = item
      }
    })
    return result
  }
// 最优版
function clone_easy(obj){
    let result=JSON.parse(JSON.stringify(obj))
    return result
}
// 乞丐版
function copy(obj){
    let res=Object.assign({},obj)
}
//问题版